Tsumura tips have different rivet counts according to pitch. I ain't one of those who think more is necessarily better. 3/8=4, .404=6 & .325=5 (from memory). Do they do this for a practical or visual/designation reason, not sure. But I do know they use 4/5/6 rivets on their exact same profile RSN Pro grade tips, so I'm sure they all work just fine.